What are blood clots and what causes them?
When we are injured, our body stops the bleeding by forming a clump of blood (a blood clot) that closes the wound. The blood clot also prevents germs from getting into the wound.
Sometimes blood clots form in the bloodstream even though there are no external injuries. If a blood vessel becomes blocked, dangerous complications like thrombosis or a stroke can occur. That very rarely happens in healthy people. But certain illnesses and risk factors can increase the likelihood of blood clots forming and causing complications.
The risk of blood clots forming in the legs (deep vein thrombosis) is higher after major surgery, for instance. Atrial fibrillation, a common type of heart rhythm problem, increases the risk of blood clots forming in the heart. If a blood clot travels through the blood stream to the brain, it can cause a stroke. Anti-clotting medication (anticoagulants) can help to prevent that from happening.